Asynchronous machines are more known as induction motors because their principle of operation is based on induction. Recalling Faraday’s law, if a wire is moved in a magnetic field, then a voltage difference is generated between its two ends. We may also say a voltage or an electromotive force is induced …

Referring to electromagnets, if a coil is connected to a DC source a magnetic field is generated in the coil. Consider now if the source is AC with a frequency of 50 Hz. Again, a magnetic field is generated, but this time its north and South Pole swap places rapidly …

In all transformers, single phase or three phase, the primary winding gets energy from the mains and the secondary winding is connected to the load(s). If the secondary circuit is turned off by a switch, there is no load on the secondary winding. Ideal Transformer Theory Nevertheless, the primary winding is …

In the same way that single-phase AC and three-phase AC are different, although both are alternating current electricity, single-phase and three-phase transformers cannot be interchanged. Nevertheless, most of what can be said for single-phase transformers is later on extended to three-phase transformers because they work based on the same principle. …

Checking the voltage/current (V/I) ratio of conductors at various temperatures shows that the resistance of most conducting materials increases linearly with temperature except at very hot or very cold temperatures. Temperature has little effect on the resistance of some alloys, such as constantan. For a few materials, including carbon and …

A three-phase load is a set of three exactly similar combinations of electric components arranged in exactly the same way (in series, parallel or other). The reason to have three-phase loads is the higher power demand. For instance, in the industry, the majority of motors are three phase, particularly the …

The fact that the three waveforms of a three-phase system are 120° apart gives desirable properties to it that makes it attractive from a practical viewpoint. The very first property of the voltages in the three-phase system is that at each instant of time the sum of all the voltages …

In any AC circuit consisting of resistors, capacitors, and inductors, either in series or in parallel, a condition can happen in which the reactive power of the capacitors and of the inductors become equal. This condition is called resonance. Simultaneous with the capacitive reactive power and the inductive reactive power being …

Phase Difference When we have two sine waves with the same frequency, the duration of one cycle is the same for both. Nonetheless, irrespective of their peak values, there are two possibilities: 1. The two waveforms reach their maximum values (and accordingly their minimum values) at the same instant. In this …

The fundamental relationship between resistance, voltage, and current can be expressed using Ohm’s law. Mathematically, it is expressed as: $V=IR$ Where, V is measured in Volts I is measured in Amps R is measured in Ohms Electric Current The electric current is a measure of the rate of flow (i.e., …

One of the most commonly used integrated circuit chips today is the operational amplifier. The operational amplifier is often simply called the op-amp. 741 Operational Amplifier Characteristics The 741 op-amp is a near-perfect amplifier. It has a high input impedance and a low output impedance, which makes it an excellent …

Definition: An integrated circuit, or IC, is a complete electronic circuit contained in one package, Figure 1. This package often includes transistors, diodes, resistors, and capacitors along with the connecting wiring and terminals. An IC is also called a chip. The transistor was invented in 1947 by Brattain, Bardeen, and …

Amplifier Definition: An amplifier is an electronic device that uses a small input signal (voltage or current) to control a larger output signal. This principle works best when the output load, or impedance, of the circuit, is greater than the input load. Examine Figure 1. The input is a microphone …

Definition: An amplifier is an electronic circuit that uses a small input signal to control a larger output signal. In electronics, amplifiers have been used since the early twentieth century. Amplification can be accomplished using vacuum tubes or semiconductor devices such as transistors or integrated circuits. The amount of amplification …

The major difference between bipolar junction transistor and field-effect transistor (FET) is that the BJT is a current device, and the FET is a voltage device. The current through the collector-emitter circuit of a BJT is controlled by the amount of current in the base-emitter circuit. A FET controls current …